海洋珍珠生物提取液对人宫颈癌Hela细胞增殖与凋亡的影响

背景:海洋珍珠生物提取液中富含锗、硒等微量元素。目的:观察海洋珍珠生物提取液对宫颈癌Hela细胞株增殖和凋亡的影响。方法:MTT法检测0,6,30,45,60,75,150mg/L海洋珍珠生物提取液对Hela细胞增殖的影响;0,6,30,60mg/L海洋珍珠生物提取液干预Hela细胞后,流式细胞仪AnnexinV和PI双染检测细胞凋亡率,PI单染法测定细胞周期,RT-PCR法测定细胞株内bcl-2,bax基因表达。结果与结论:6～45mg/L海洋珍珠生物提取液对Hela细胞增殖有抑制作用,表现出浓度依赖性和时间依赖性(P<0.05),在60～150mg/L范围内只表现出了浓度依赖性(P<0.05),无时间依赖性。6～60mg/L海洋珍珠生物提取液呈浓度依赖性促进Hela细胞凋亡,使细胞阻滞在G1期;30,60mg/L海洋珍珠生物提取液可降低细胞内bcl-2mRNA表达,升高baxmRNA表达。说明海洋珍珠生物提取液以浓度依赖性的方式抑制Hela细胞增殖,并通过降低bcl-2mRNA,升高baxmRNA来诱导细胞凋亡。     

转染bcl-2反义寡核苷酸诱导宫颈癌Hela细胞凋亡的体外实验研究

目的 :体外研究bcl- 2反义寡核苷酸对人宫颈癌Hela细胞凋亡的影响 ,旨在寻求提高肿瘤细胞放射敏感性的方法。方法 :(1)免疫组化、半定量RT -PCR法鉴定ASODN的有效性。 (2 )Giemsa染色、流式细胞术凋亡指数 (AI)、DNALadder检测细胞凋亡。结果 :(1)转染后 ,免疫组化结果示Bcl- 2蛋白表达降低 ;半定量RT -PCR结果显示bcl- 2mRNA表达较对照组明显减弱 (P <0 0 5 )。 (2 )转染后 ,Giemsa染色可见凋亡小体 ;流式细胞术结果显示转染后AI为 :6 6 0± 0 70 % ,明显高于对照组 1 79± 0 19% (P <0 0 5 ) ;DNALadder呈现具有凋亡特征的梯带。结论 :(1)本实验所设计的ASODN能有效地抑制bcl- 2基因的表达。 (2 )转染ASODN (bcl-2 )能够显著增加Hela细胞凋亡。进而有望通过转染ASODN提高肿瘤细胞的放射敏感性。     

三氧化二砷对K562/ADM耐药细胞凋亡抑制的逆转作用

目的:研究三氧化二砷(As2O3)诱导白血病K562/ADM耐药细胞凋亡的分子机制。方法:采用MTT比色法检测K562/ADM耐药细胞增殖活性,细胞形态学和annexinV /PI双染色检测细胞凋亡,RT-PCR检测mdr1、bcl-2和caspase-3基因mRNA的表达水平,流式细胞法(FCM)测定P-糖蛋白(P -glycoprotein,P-gp)和bcl-2蛋白表达及caspase-3活性。结果:As2O3显著抑制K562/ADM耐药细胞的增殖;经 As2O3处理后细胞形态上出现典型的凋亡改变,annexinV /PI双染显示凋亡细胞明显增加;mdr1mRNA表达和P-gp合成明显降低,凋亡抑制基因bcl-2mRNA及其蛋白bcl-2表达下调, caspase-3mRNA表达和caspase-3活性显著增强。结论:As2O3诱导K562/ADM耐药细胞凋亡,其主要机制可能为As2O3抑制 mdr1和bcl-2基因表达,逆转耐药白血病细胞因bcl-2和P-gp高表达所介导的凋亡抑制。     

大蒜素和顺铂联合作用对人视网膜母细胞瘤细胞凋亡影响的研究

目的:探讨大蒜素和顺铂联合应用对人视网膜母细胞瘤细胞的抑制作用,及其对人视网膜母细胞瘤细胞凋亡的影响.方法:人视网膜母细胞瘤细胞株,经复苏,孵育,传代分为4个实验组,分别用大蒜素、顺铂、大蒜素和顺铂联合处理人视网膜母细胞瘤细胞,在不同时间(24、48、72 h)观察细胞的形态.并应用免疫细胞化学SP法检测不同处理条件下和各时间点bcl-2和PDCD5的表达情况.结果:人视网膜母细胞瘤细胞在大蒜素、顺铂以及大蒜素和顺铂联合作用下,细胞生长增殖受到抑制,与对照组的人视网膜母细胞瘤细胞相比形态学变化明显.大蒜素、顺铂及两者联合作用均可以下调人视网膜母细胞瘤细胞中bcl-2的表达,上调人视网膜母细胞瘤细胞中PDCD5的表达,大蒜素15μg/mL和顺铂3μg/mL联合用药可增强对人视网膜母细胞瘤细胞的生长抑制,与大蒜素15μg/mL、顺铂3μg/mL单独处理人视网膜母细胞瘤细胞比较,下调bcl-2表达和上调PDCD5表达的作用差异有统计学意义(P<0.05).结论:大蒜素和顺铂联合用药作用强于单独用药,可进一步提高药物对肿瘤细胞的生长抑制. 胞生长增殖受到抑制,与对照组的人视网膜母细胞瘤细胞相比形态学变化明显.大蒜素、 铂及两者联合作用均可以下调人视网膜母细胞瘤细胞中bcl-2的表达,上调人视网膜母细胞瘤细胞中PDCD5的表达,大蒜素15μg/mL和顺铂3μg/mL联合用药可增强对人视网膜母细胞瘤细胞的生长抑制,与大蒜素15μg/mL、顺铂3μg/mL单独处理人视网膜母细胞瘤细胞比较,下调bcl-2表达和上调PDCD5表达的作用差异有统计学意义(P<0.05).结论:大蒜素和顺铂联合用药作用强于单独用药,可进一步提高药物对肿瘤细胞的生长抑制. 胞生长增殖受到抑制,与对照组的人视网膜母细胞瘤细胞相比形态学变化明显.大蒜素、 铂及两者联合作用均可以下调人视网膜母细胞瘤细胞中bcl-2的表达,上调人视网膜母细胞瘤细胞中PDCD5的表达,大蒜素15μg/mL和顺铂3μg/mL联合用药可     

姜黄素对人多发性骨髓瘤细胞表达Survivin、Bcl-2、Bax的影响

为探讨姜黄素对人多发性骨髓瘤细胞RPMI8226的抑制生长和诱导凋亡的作用机制,应用MTT法检测姜黄素对肿瘤细胞的杀伤效应;用流式细胞术（FCM）分析姜黄素作用后肿瘤细胞凋亡及细胞周期的变化;用RT-PCR方法检测Survivin、Bcl-2、Bax mRNA水平的变化。结果表明：姜黄素明显抑制RPMI8226细胞的增殖,并表现为时间、剂量依赖性,24、48小时IC50值分别为12.15μmol/L、4.9μmol/L;凋亡率由10.6%增加到36.9%（p〈0.05）,细胞发生G2/M期阻滞;RPMI8226细胞细胞强表达Survivin、Bcl-2,弱表达Bax。RPMI8226细胞经10μmol/L姜黄素处理24小时后,survivin、Bcl-2 mRNA表达下调,而Bax表达上调。结论：姜黄素抑制多发性骨髓瘤细胞RPMI8226增殖,并诱导凋亡。姜黄素的抗瘤机制可能与凋亡相关蛋白survivin、bcl-2、bax在转录水平的调节有关。     

细胞周期蛋白E2反义脱氧寡核苷酸对K562细胞增殖及凋亡的调控作用

目的 研究细胞周期蛋白E2 (cyclin E2)反义脱氧寡核苷酸(ASON)对人红白血病细胞K562增殖的调控作用.方法 采用反义技术合成ASON并与K562细胞共培养.用四甲基偶氮唑蓝(MTT)法检测转染ASON和脂质体lipofectamineTM 2000后的细胞活力,逆转录-聚合酶链式反应(RT-PCR)方法检测转染细胞cyclin E2 mRNA表达水平及流式细胞术和形态学观察检测细胞凋亡.结果 Cyclin E2特异的ASON能显著地抑制cyclin E2mRNA水平的表达(F=26.442,P＜0.01);白血病细胞的生长明显受抑制(P＜0.01),细胞凋亡明显增加.结果 表明反义脱氧寡核苷酸能有效地抑制K562细胞的增殖,抑制K562细胞cyclin E2 mRNA表达上调,并显著地诱导细胞凋亡.结论 脂质体转染cyclin E2的反义寡核苷酸能够有效地抑制K562细胞cyclin E2 mRNA的表达,同时对白血病细胞K562的生长有明显的抑制作用,并可诱导K562细胞凋亡.提示cyclin E2在细胞周期调控中起作用,cyclinE2基因有望作为反义技术治疗急性白血病中的一个较有意义的新靶点.     

塞来昔布对淋巴瘤细胞株Namalwa增殖及凋亡的影响

研究发现,环氧合酶-2(Cyclooxygenase-2,COX-2)与肿瘤的关系密切,其选择性抑制剂塞来昔布(Celecoxib)可以抑制多种肿瘤细胞的生长,具有广泛的抗肿瘤活性.我们通过观察塞来昔布对人B细胞淋巴瘤细胞株Namalwa细胞增殖、凋亡及细胞周期的影响,并检测bcl-2 mRNA在细胞中的表达情况,旨在探讨塞来昔布对恶性淋巴瘤细胞的抗肿瘤活性及作用机制,为其应用于恶性淋巴瘤的临床治疗提供实验及理论依据.     

姜黄素致HepG-2细胞的凋亡作用及对bcl-2/bax表达的影响

目的:研究姜黄素致人肝癌HepG-2细胞的凋亡作用及bax与bcl-2 mRNA表达的变化,为姜黄素的临床应用提供实验依据.方法:当HepG-2细胞处于对数生长期时,分别加入不同浓度(0、2.5、5、10、20、30 mg/L)的姜黄素处理48 h,MTT试验检测细胞的抑制率;流式细胞仪检测细胞凋亡率;实时荧光定量PCR检测bax和bcl-2mRNA的含量.结果:随着姜黄素浓度的增高,其对HepG-2细胞的抑制作用逐渐增强.当姜黄素浓度为30mg/L时,其抑制率达到(58.23±2.56)%,IC50=25.44 mg/L,而细胞的凋亡率由对照组的(1.1±0.3)%上升到(38.4±1.5)%;bax和bcl-2分别是对照组的(5.00±0.55)倍和(0.28±0.05)倍.结论:姜黄素能抑制HepG-2细胞的生长,诱导细胞凋亡,它的分子机制可能是上调bax基因和下调bcl-2基因的表达.     

应用Cyclin D1和bcl-2靶标的siRNA慢病毒载体构建和鉴定

背景:近年来,与骨肉瘤耐药相关的基因研究大多局限于单个基因或单个通路.而进行细胞凋亡和细胞周期调控双通道同时阻断有可能逆转药物耐受机制.目的:构建bcl-2和cyclin D1特异性siRNA慢病毒载体,拟将其转入骨肉瘤耐药细胞株,探讨对骨肉瘤耐药性的逆转作用.方法:采用限制性内切酶酶切、T4DNA连接酶连接等方法,将bcl-2和cyclin D1基因分别插入慢病毒载体pSIH1-H1-copGFP shRNA Vector中,构建bcl-2和cyclin D1与pSIH1-H1-copGFP共表达的慢病毒载体(pSIH1-H1-copGFP-bcl-2-siRNA和pSIH1-H1-copGFP-cyclinD1-siRNA).构建成功后的慢病毒质粒系统和pPACK包装质粒共转染293T细胞,过滤,浓缩病毒,利用荧光蛋白作为报告基因,对病毒滴度和感染效率进行检测.结果与结论:4对bcl-2和cyclin D1特异性siRNA与双酶切慢病毒载体pSIH1-H1-copGFP shRNA Vector连接成功.共转染293T细胞包装病毒并浓缩后滴度达1.14×104 jfu/μL,适合感染目的细胞.实时荧光定量PCR检测结果显示对bcl-2和cyclinD1基因的干扰效率最高分别达88%和87%.证实将siRNA技术应用于bcl-2和cyclin D1,能够构建出有效的bck2和cyclin D1特异性siRNA慢病毒载体.     

乙醇诱导大鼠骨髓间充质干细胞的凋亡机制

背景:有研究表明乙醇可诱导骨髓间充质干细胞凋亡并引起成骨细胞和破骨细胞数量减少,但乙醇对骨髓间充质干细胞凋亡的影响以及作用机制目前尚不十分清楚。目的:观察乙醇对大鼠骨髓间充质干细胞凋亡、线粒体功能的影响及bcl-2、Caspase-3表达的变化。方法:应用全骨髓培养法分离培养SD大鼠骨髓间质干细胞,置于0,100,200,300,400,500,600,700,800,900mmol/L乙醇中作用24h,MTT法进行细胞毒性药物实验;置于0,100,200,300,400,500mmol/L乙醇中作用6,12,24h,AnnexinV/PI双标记法流式细胞仪检测细胞凋亡和线粒体膜电位变化情况;置于0,427mmol/L乙醇中作用24h,RT-PCR法检测与凋亡有关的基因bcl-2和Caspase-3mRNA表达水平。结果与结论:MTT检测结果显示427mmol/L是乙醇对大鼠骨髓间充质干细胞生长的半数抑制浓度;AnnexinV/PI检测结果表明,与0mmol/L组比较,随作用时间的延长与乙醇浓度的增加,骨髓间充质干细胞凋亡率及线粒体跨膜电位的破坏水平明显升高(P<0.05)。与0mmol/L组比较,乙醇作用24h后427mmol/L组bcl-2mRNA表达水平下降,Caspase-3mRNA表达水平增加(P<0.05)。说明乙醇能诱导大鼠骨髓间充质干细胞凋亡,凋亡的发生可能与线粒体膜电位破坏、线粒体功能障碍、bcl-2和Caspase-3激活有关。     

Silencing Bcl-2 in models of mantle cell lymphoma is associated with decreases in cyclin D1, nuclear factor-kappaB, p53, bax, and p27 levels

Molecular mechanisms responsible for lymphoma resistance to apoptosis often involve the bcl-2 pathway. In this study, we investigated the cell signaling pathways activated in bcl-2-overexpressing human mantle cell lymphoma cell lines (JVM-2 and Z-138) that have been treated with oblimersen, a molecular gene silencing strategy that effectively suppresses bcl-2 in vitro and in vivo. Z-138 cells expressed higher levels of bcl-2 and were more sensitive to the effects of bcl-2 silencing, mediated by oblimersen or bcl-2 small interfering RNA, in vitro. Tumors derived following injection of Z-138 cells were sensitive to oblimersen as judged by decreases in tumor growth rate and decreases in cell proliferation (as measured by Ki-67). Immunohistochemistry and Western blot analysis of oblimersen-treated Z-138 tumors revealed a dose-dependent decrease in bcl-2 levels and an associated increase in the proapoptotic proteins caspase-3 and caspase-9. Silencing bcl-2 in Z-138 xenografts revealed an associated dose-dependent suppression of bax, a decrease in nuclear factor-kappaB and phospho-nuclear factor-kappaB, and transient loss of p53 levels. Coimmunoprecipitation studies suggest that the latter observation is mediated by an association between bcl-2 and phospho-mdm2. Bcl-2 silencing also led to p27 down-regulation and coimmunoprecipitation studies point to a role for bcl-2 in regulation of p27 localization/degradation. Bcl-2 silencing was also correlated with loss of cyclin D1a protein levels but not cyclin D1b levels. Coimmunoprecipitation studies indicate that bcl-2 may mediate its effects on cyclin D1a via interaction with p38 mitogen-activated protein kinase as well as a previously unreported interaction between bcl-2 and cyclin D1a.     

Antisense oligonucleotides directed at the bcl-xl gene product augment chemotherapy response in mesothelioma

OBJECTIVE: Malignant pleural mesothelioma (MPM) is resistant to both conventional chemotherapy and apoptosis. The bcl-2 family proteins are major determinants of apoptotic homeostasis. MPM lines and tumors routinely overexpress the anti-apoptotic protein BCL-XL. We have previously shown that antisense inhibition of BCL-XL in MPM cells leads to apoptosis. We sought to determine whether antisense oligonucleotides directed at the bcl-xl gene product would augment response to a conventional chemotherapeutic agent in human mesothelioma cell lines. METHODS: The human MPM cell lines REN and I-45 were exposed to two bcl-xl antisense oligonucleotides (15999, 16009) and one sense oligonucleotide (113529) construct at varying doses, followed by IC(50) cisplatin. Cellular viability was assessed by a calorimetric assay, and apoptosis was evaluated by Hoechst staining, Annexin V staining, and sub-G(1) fluorescence-activated cell sorter analysis. Western blot analysis of BCL-2 family proteins was performed following single agent and combined treatment. Isobologram mathematical analysis was used to determine whether or not combination therapies were additive or synergistic. RESULTS: Cell viability was most affected with the 15999 antisense oligonucleotides plus IC(50) cisplatin combination (70% of I-45 and 90% of REN cells killed), and apoptosis was markedly increased with this combination by all measures. Western blot demonstrated 15999 antisense oligonucleotides construct down-regulation of BCL-XL, but no further effect on expression of BCL-2 proteins with cisplatin. Isobologram analysis demonstrated 15999 + cisplatin synergistic effect. CONCLUSIONS: Exposure of human MPM cells to bcl-xl antisense oligonucleotides sensitizes human mesothelioma cells to the conventional chemotherapeutic agent cisplatin. Similar approaches using a combination of molecular and conventional treatment may have clinical utility for this tumor.     

六亚甲基二乙酰胺对急性白血病细胞株HL-60和U937分化、凋亡的影响及其机制

目的　研究六亚甲基二乙酰胺 (HMBA)体外诱导HL 6 0和U937细胞分化、凋亡的作用及其机制。方法　流式细胞仪检测细胞分化抗原CD1 1b、CD1 4,细胞凋亡标记Annexin Ⅴ以及进行细胞周期分布和细胞内cyclinD、cyclinE、p2 7抗原的分析 ,RT PCR检测c myc、Rb、Bcl 2基因mRNA的表达。结果　HL 6 0、U937细胞经HMBA处理 72h后CD1 1b表达显著增高 ,高剂量HMBA促使Annexin Ⅴ表达增加。HMBA阻滞HL 6 0、U937细胞于G0 G1 期 ,并使该两种细胞内cyclinE表达显著下降 ,cyclinD、p2 7表达显著增高 ,呈剂量依赖关系 ;HMBA可使HL 6 0、U937细胞c myc、Bcl 2mRNA表达下调 ,而RbmRNA在HL 6 0细胞表达上调 ,在U937细胞则无显著改变。结论　HMBA能诱导HL 6 0、U937细胞出现明显的分化 ,高剂量的HMBA有促使HL 6 0、U937细胞凋亡的倾向 ,其机制可能是通过影响细胞周期调控分子以及有关的增殖分化相关基因的表达 ,从而抑制细胞增殖 ,促进细胞分化。     

胃肠道间质瘤中Ki一67、cyclinD1和bcl-2的表达与危险度及预后的关系

目的探讨胃肠道间质瘤（GIST）中Ki-67增殖指数（u）、cyclinDl和bcl-2的表达与危险度及预后的关系。方法对76例确诊的GIST应用免疫组化SP法检测Ki--67、cyclinD1和bcl-2的表达,分析与危险度和预后的关系。结果危险度极低、低、中和高度分别为10、23、18和25例;随访61例,其中42例健在,12例死于GIST,7例死于其他原因。Ki-67LI〉5％与核分裂象〉5／50HPF、肿瘤直径〉5cm及危险度中高有关（P〈0．05）;cyclinD1和bcl-2的阳性表达与核分裂象、肿瘤大小无关而与中高危组相关（P〈0．05）。结论Ki-67、cyclinD1和bcl-2在GIST中、高危险度组高表达,可作为预测危险度和预后有用的指标,Ki-67LI可作为独立指标。     

脂质体转染细胞周期素A反义脱氧寡核苷酸对HL-60细胞增殖及凋亡的调控作用

目的探讨脂质体转染细胞周期素A(cyclin A)反义脱氧寡核苷酸(ASON)对HL-60细胞增殖及凋亡的影响.方法采用脂质体转染技术将cyclin A ASON与HL-60细胞共同培养,用MTT法绘制细胞生长曲线,用电镜、细胞原位凋亡检测(POD)等方法观察细胞凋亡,用流式细胞术(FACS)及RT-PCR法检测cyclin A、bcl-2表达,并通过裸鼠成瘤实验验证cyclin A在白血病发生中的作用.结果脂质体转染cyclin A ASON组和cyclin A ASON组的HL-60细胞生物抑制率分别为68.9%和24.8%(P<0.01).脂质体转染cyclin A ASON组cyclin A及bcl-2表达水平(1.1%和21.9%)较对照组(38.8%和65.0%)明显减低(P值均<0.01),并能检测出DNA断裂,观察到凋亡细胞.裸鼠实验中发现脂质体转染cyclin A ASON组与对照组相比,其成瘤率低,成瘤时间延长,同一时间成瘤的瘤体体积明显缩小.结论脂质体转染cyclin A ASON能在体外及动物体内明显抑制白血病细胞的生长,且有诱导细胞凋亡的作用,可能会成为基因治疗的一个新靶点.     

超声微泡介导bcl-xl基因抗视网膜神经节细胞凋亡作用的实验研究

目的评价超声微泡介导bclxl基因抗视网膜神经节细胞(RGCs)凋亡的作用。方法体外混合培养LongEvans大鼠RGCs,并建立N甲基D天冬氨酸(NMDA)损伤的RGCs凋亡模型。将体外培养的RGCs分为A组(正常对照组),B组(NMDA组),C组(bclxl转染 NMDA组);其中C组在加入NMDA前48h用超声微泡介导bclxl转染RGCs。转染48h后采用免疫组化分析转染细胞和未转染细胞的bclxl蛋白水平;加入NMDA36h后采用吖啶橙/溴化乙锭(AO/EB)双荧光染色检测细胞凋亡的形态特征,琼脂糖电泳检测细胞凋亡DNA片断。结果免疫组化检测表明转染细胞与未转染细胞的bclxl蛋白表达水平有差异,AO/EB检测发现B组可见大量凋亡小体,C组可见少许凋亡细胞。琼脂糖电泳检测亦发现B组呈典型的DNA“梯度”条带,而A组和C组无明显的DNA“梯度”条带。结论超声微泡介导bc1xl基因抗视网膜神经节细胞凋亡有一定作用,有可能为视网膜视神经疾病的基因治疗提供一种新的方法。     

Cyclin D3 is down-regulated by rapamycin in HER-2-overexpressing breast cancer cells

Rapamycin and its analogues are being tested as new antitumor agents. Rapamycin binds to FKBP-12 and this complex inhibits the activity of FRAP/mammalian target of rapamycin, which leads to dephosphorylation of 4EBP1 and p70 S6 kinase, resulting in blockade of translation initiation. We have found that RAP inhibits the growth of HER-2-overexpressing breast cancer cells. The phosphorylation of mammalian target of rapamycin, p70 S6 kinase, and 4EBP1 is inhibited by rapamycin and cells are arrested in the G1 phase, as determined by growth assays, fluorescence-activated cell sorting analysis, and bromodeoxyuridine incorporation studies. Rapamycin causes down-regulation of cyclin D3 protein, retinoblastoma hypophosphorylation, loss of cyclin-dependent kinase (cdk) 4, cdk6, and cdk2 activity. The half-life of cyclin D3 protein decreases after rapamycin treatment, but not its synthesis, whereas the synthesis or half-life of cyclin D1 protein is not affected by the drug. Additionally, rapamycin caused accumulation of ubiquitinated forms of cyclin D3 protein, proteasome inhibitors blocked the effect of rapamycin on cyclin D3, and rapamycin stimulated the activity of the proteasome, showing that the effect of rapamycin on cyclin D3 is proteasome proteolysis dependent. This effect depends on the activity of HER-2 because Herceptin, a neutralizing antibody against HER-2, is able to block both the induction of proteasome activity and the cyclin D3 down-regulation due to rapamycin. Furthermore, inhibition of HER-2 gene expression by using small interfering RNA blocked the rapamycin effects on cyclin D3. These data indicate that rapamycin causes a G1 arrest in HER-2-overexpressing breast cancer cells that is associated with a differential destabilization and subsequent down-regulation of cyclin D3 protein.     

Inhibition of basal and mitogen-stimulated pancreatic cancer cell growth by cyclin D1 antisense is associated with loss of tumorigenicity and potentiation of cytotoxicity to cisplatinum.

Cyclin D1 belongs to a family of protein kinases that have been implicated in cell cycle regulation. Recent studies have demonstrated that elevated cyclin D1 levels correlate with decreased survival in human pancreatic cancer. In this study we expressed in a stable manner a cyclin D1 antisense cDNA construct in PANC-1 human pancreatic cancer cells. Expression of the antisense construct caused a decrease in cyclin D1 mRNA and protein levels and in cyclin D1-associated kinase activity. Antisense expressing clones displayed significantly increased doubling times, decreased anchorage-dependent and -independent basal growth, and complete loss of tumorigenicity in nude mice. EGF, FGF-2, and IGF-I enhanced mitogen-activated protein kinase activity in antisense expressing clones, but failed to stimulate their proliferation. In contrast, all three growth factors were mitogenic in parental cells. Furthermore, the inhibitory effect of cisplatinum on cell proliferation was enhanced markedly in the antisense expressing clones. These findings indicate that cyclin D1 overexpression contributes to abnormal growth and tumorigenicity in human pancreatic cancer and to the resistance of pancreatic cancer to chemotherapeutic agents.     

脉冲电场联合野生型p53基因诱导人宫颈癌Hela细胞凋亡

背景:在前期研究基础上,设想将基因电转染作为脉冲电场治疗恶性肿瘤的辅助方法。目的:探讨脉冲电场联合抑癌基因野生型p53基因诱导人宫颈癌hela细胞发生凋亡及相互作用。方法:采用空质粒及含有野生型p53的质粒转染Hela细胞得到Hela-vector、Hela-p53细胞,将Hela细胞、Hela-vector和Hela-p53细胞分别施加固定脉宽100μs、频率1Hz、脉冲数8个、电场强度为1500V/cm的脉冲电场处理。结果与结论:相同参数脉冲电场作用于各组细胞12h后,MTT结果显示Hela-p53组细胞吸光度明显低于Hela组(P<0.05);流式细胞仪及RT-PCR检测结果显示Hela-p53组的早期凋亡率和p53mRNA表达较Hela组明显增加;Westernbolt及激光共聚焦显微镜结果显示与Hela组比较,Hela-p53组细胞Bax蛋白表达明显上升,而Bcl-2蛋白则明显下降,Casepase-3相对荧光强度明显增强。表明野生型p53基因对宫颈癌Hela细胞生长有明显的抑制作用,野生型p53基因可以提高脉冲电场诱导宫颈癌Hela细胞凋亡的作用。